1. Field of the Invention
This invention relates to a fluid torque converter, which permits connecting a pump wheel and a turbine wheel together directly by means of a direct-coupling clutch capable of connecting and disconnecting the pump wheel and turbine wheel to and from each other.
2. Description of the Prior Art
A direct-coupling clutch for a fluid torque converter for vehicles, such as automobiles, has been used to directly couple a pump wheel and a turbine wheel for preventing slippage between the pump wheel and turbine wheel to improve the torque transmission efficiency. In such a direct-coupling clutch, a shock occurs when the clutch is put in a coupled state, to not only give the driver an unpleasant feeling but also spoil the durability of the direct-coupling clutch and power transmission system. When the fluid torque converter is in a directly-connected state, the fluctuation of an engine torque is transmitted directly to the power transmission system. Especially, when the engine is decelerated suddenly, a shock occurs and is transmitted to the power transmission system. This inevitably deteriorates the driving comfort.